Note presenting an investigation on a supercharger inlet elbow designed to have a uniform velocity distribution at the outlet with a minimum pressure loss through the bend. The effects of a vane, an impeller-shaft housing, and the combination of the two on the outlet-velocity distribution and total pressure drop through the elbow were determined.

Note presenting a method of stress analysis for a continuous beam-column supported by deflectional and rotational springs. The principal feature of the method is the use of a relaxation procedure to determine the deflections and rotations of the supports. The shears and moments at the supports and between the supports can then be calculated with the aid of sample equations and graphs.

From Summary: "The temperature distribution of a two-row radial engine in a twin-engine airplane has been investigated in a series of flight tests. The test engine was operated over a wide range of conditions at density altitudes of 5000 and 20,000 feet; quantitative results are presented showing the effects of flight and engine variables upon average engine temperature and over-all temperature spread. Discussions of the effect of the variables on the shape of the temperature patterns and on the temperature distribution of individual cylinders are also included."

Note presenting temperatures of a turbosupercharger rotor measured in flight for a variety of conditions by thermocouples, the leads of which were brought away from the turbine by means of rotating slip rings and stationary brushes. A consistent and almost linear relation was shown between turbine temperature at the outer edge of the rim and the effective exhaust-gas temperature at the surfaces of the blades on three successive flights at cruising power.

The infrared spectra of spiropentane, methylenecyclobutane, and 2-methyl-1-butene were measured in the region from 3 to 14 microns with a rock salt prism spectrometer of medium dispersion. The pure samples were prepared at the NACA Cleveland Laboratory. The vapors of these three C5 hydrocarbons were investigated at room temperature and at pressures in the range from 80 to 300 millimeters of mercury absolute in a 10-centimeter cell. The spectra were compared with each other and with Ramon spectra for the same compounds.

This document details technical activities in the 100, 200, 300 areas as well as activities in the chemical development, statistical studies, and Laboratories Departments for the period of October 6 through October 12, 1946. (FI)

This memorandum provides an estimate of the life of manufacturing piles.

In August 1946 it was discovered that two effluent lines near the Columbia River at Hanford were damaged. The upstream effluent line has broken off 37 fact from the shoreline and the downstream effluent line had been bent and partly broken seventeen feet from shoreline and has swung downstream to a point about 50 feet from shorelines. This study was made to determine how fast and in what fashion the temperature of the effluent water is dissipated in the Columbia River under the present conditions and to compare this to a previous survey made when the effluent lines were believed to be in their original position.

Recent data show that test hole samples out from the center of a bar show greater expansion rates than do samples out from the edge of a bar. The previously noticed irregularities in expansion of test hole samples are attributed to this phenomenon. For unexplained reasons, the expansion of the graphite piles is in close agreement with the smaller expansion rates shown by test hole samples rather than with the larger rates. It is recommended that the neoprene coal on the far side of the F pile be placed before the end of the year. It is recommended that the neoprene seal on the near side of the D Pile be replaced after replacement neoprene is on hand. It is recommended that the compressed cork and about 4 inches of the cement block was in back of the Third Safety Tanks at the D Pile be removed at the time of replacement of the neoprene seal, and that the resulting gap be covered with a flexible air-impermeable membrane such as rubberized canvas. Actual measurement of the length of graphite between the gun barrels of Tube 3671-B confirms the predicted end-wise expansion of the graphite as deduced from jacking tests on …

Samples of pile graphite, irradiated in a test-hole at Hanford for 15 months, have been assayed for radioactive C{sup14}, yielding 0.38 ± 0.04 microcuries per gram. At this level of activity, the pile graphite contains very valuable amounts of C{sup14}. The relation between the above assay and the probable average assay of pile graphite is discussed, and it is concluded that the latter is almost certainly above 0.3 uc/ gram. Controlled oxidation of this graphite, either with oxygen at ~ 750°C, or with chromic acid "cleaning solution" at room temperature, yields early fractions which are highly enriched in C{sup14}. Concentrations of 5-fold with oxygen, and 50-fold with CRO{sub3}, have been observed. The relation between the observed enrichment and the Wigner effect is discussed, and a mechanism accounting for the observations put forward. According to this, about 25% of the stable carbon atoms in the lattice have been displaced by Wigner effect, a large fraction of which have healed the migrating to crystal edges. All the C{sup14} atoms have been displaced, and the same fraction of these migrate to the edges. The enrichment then results from surface oxidation, in the oxygen case. Predictions are made on the basis of this hypothesis. …

Report presenting fatigue testing to determine the effect of bolt fit on the lifetime of lap joints of 24S-T Alclad sheet of various thicknesses joined by steel bolts and designed for sheet failure under repeated loading. Results regarding joints with countersunk bolts, joints with bolts drawn to high initial torque, joints with bolts of different diameters, multibolt joints with nonuniform bolt fit, fatigue strength of the sheet material, friction in bolted lap joints, and bolt slip during testing are provided.

An account is given of the Possio theory of non stationary flow for small disturbances in a two-dimensional supersonic flow and of its application to determination of the aerodynamic forces on an oscillating airfoil. Further application is made to the problem of wing flutter in the degrees of freedom - torsion, bending, and aileron torsion. Numerical tables for flutter calculations are provided for numerous values of the Mach number greater than unity. Results for bending-torsion wing flutter are discussed. The static instabilities of divergence and aileron reversal are examined as is a one degree of freedom case of torsional oscillatory instability.

Report presenting flight tests of an all-movable tail with geared unbalancing tabs installed on the Curtiss XP-42 airplane. The control configuration used involved the pilot's stick connected directly to the tail and the tabs changed from servotabs to geared unbalancing tabs. Results regarding dynamic longitudinal stability and control, static longitudinal stability, elevator control, elevator hinge-moment characteristics, and elevator control in landing, in flight, and in spins are provided.

Report presenting the performance characteristics of a 20-inch ramjet opeerating with preheated unleaded 62 octane fuel. The results of the investigation indicated an improvement in the combustion efficiency and operating range of the ramjet when using preheated fuel.

"Flight tests were conducted on a R-2800-21 engine in the P-47G airplane to determine the effect on the wall temperatures of cylinder 10 of throttling the charge in the intake pipe and of injecting a water-ethanol coolant into the intake pipe. Cylinder 10 was chosen for this investigation because it runs abnormally hot (head temperatures of the order of 45 F higher than those of the next hottest cylinder) at the medium and high-power conditions. Tests with interchanged cylinders showed that the excessive temperatures of cylinder 10 were inherent in the cylinder location and were not due to the mechanical condition of the cylinder assembly" (p. 1).

"The data obtained from cooling tests of an R-2800-21 engine installed in a P-47G airplane were studied to determine which engine and airplane operation variables were mainly responsible for the extremely uneven temperature distribution among the 18 engine cylinders obtained at the medium and high engine-power conditions. The tests consisted of flights at altitudes from 5000 to 35,000 feet for the normal range of engine and airplane operation. The results of the study showed that a flow condition in the induction system associated with the wide-open throttle position, which affected either the fuel air or charge distribution, was primarily responsible for the uneven temperature distribution" (p. 1).

"The cooling characteristics of three R-1830-94 engines, two of which were mounted in a test stand and the other in a B-24D airplane, were investigated and the results were compared. The flight tests were made at a pressure altitude of 7000 feet; the test-stand runs were made at ground-level atmospheric conditions. Three cooling runs were made for each engine: variable cooling-air pressure drop, variable carburetor-air flow, and variable fuel-air ratio" (p. 1).

"An approximate method for determining the convective cooling requirement in the laminar boundary-layer region of a body of revolution in high-speed flight was developed and applied to an example body. The cooling requirement for the example body was determined as a function of Mach number, altitude, size, and a surface-temperature parameter. The maximum value of Mach number considered was 3.0 and the altitudes considered were those within the lower constant-temperature region of the atmosphere (40,000 to 120,000 ft.)" (p. 463).

"An analysis based on nonboiling forced-convection heat-transfer theory is made of the cooling processes in liquid-cooled engine cylinders. Semiempirical equations that relate the average head and barrel temperatures with the primary engine and coolant parameters are derived. A correlation method based on these equations is applied to data obtained from previously reported investigations, which were conducted over large ranges of engine and coolant conditions with two liquid-cooled cylinders using water and various aqueous ethylene glycol solutions as coolants" (p. 285)

From Summary: "Results are presented of light tests made to determine the effect of flap deflection on the lateral control characteristics of a modified Brewster F2A-2 airplane equipped with partial-span narrow-chord ailerons on the trailing edge of a full-span NACA slotted flap. The investigation included determination of the rolling and yawing characteristics of the airplane in abrupt aileron rolls with the slotted flap at various settings ranging from 0 degree to about 40 degrees. The results showed that the effectiveness of the ailerons was greatly reduced at flap deflections greater than about 20 degrees. For flap deflections up to about 20 degrees, the aileron effectiveness was about the same as with flaps retracted, but the adverse yawing velocity developed in the abrupt aileron rolls was somewhat increased."

The favorible attention being given graphite as a fuel rod material calls attention to the need for preventing diffusion of fission products from the fuel rods. The methods of prevention include painting the surface of the rod with an impermeable organic synthetic composition, enclosing the rods in metal cans, electroplating the rods with a suitable metal, or covering the surface with some type of inorganic ceranmic glaze. Each of these methods is evaluated as to feasibility. (M.H.R.)

Certain difficulties have been encountered in attempts to substitute a 'one-step' casting process, developed at Iowa State College, for the 'normal' process generally used for the production of extrusion billets. In the 'one-step' process molten metal is delivered from the reduction bomb to the billet mold instead of allowing the metal to solidify in the bomb with subsequent vacuum remelting of the biscuit metal before casting in the billet mold. Routine analyses had failed to establish significant differences in the composition of normal and one-step metal. The one-step billets had been extruded satisfactorily, and finished slugs were prepared and subjected to the usual canning operation. In subsequent tests however, it was found that a large percentage of the canned slugs were badly defective. An investigation was requested to determine the differences in composition or structure of the X-C and normal metal which would account for the failure of the X-C slugs. Samples of the failed slugs and of metal from various stages of both the one-step and normal processes were supplied by Madison Square Area, for comparison on the basis of analyses, microstructure, or such other tests as seemed desirable.

From abstract: "In estimating the activities of β-emitting materials used in the Biology Section, most measurements were made with Geiger-Mueller counters, although Lauritsen electroscopes were used in early work. All samples were mounted on flat porcelain capsules."

From abstract: "Several different techniques were used to introduce tracer quantities of plutonium into the lungs of rats. When aerosols were produced by atomizing aqueous solutions of the nitrates it was found that approximately 20 per cent of the dose was absorbed and deposited in the skelton [sic] with tetra-, hexa-, and trivalent plutonium. Thus with these compounds, the lungs represent a more dangerous portal of entry than either oral (0.05 per cent) or intramuscular (13 per cent) administration. Tetravalent Pu was eliminated most slowly from the lung, the average half-time during the first month being 15 days. But when citrate was added to complex the Pu, over 70 per cent was eliminated within 1 day. This was accompanied by a deposition of over 30 per cent in the skelton [sic] and over 20 per cent in the liver. Presumably citrate breaks up the insoluble colloid in which Pu exists in the lungs. Complexing with cupferron which, unlike citrate, produces a "fat soluble" compound, greatly diminished the extent of absorption from the lungs. Plutonium oxide smokes which were produced at high temperatures were eliminated more slowly from the lungs (average half time of 30 days during the first month) and …